There are there main forms Acute Mountain Sickness (AMS), High Altitude Cerebral Edema (HACE), High Altitude Pulmonary Edema (HAPE). Environmental temperature decreases at an overage of 6.5 degrees Centigrade per 1000m gains in elevation. Due to the cold the amount of oxygen required to maintain the body temperature also increases.
Ultraviolet (UV) light penetration increases four per cent every 300 m gain in altitude, which increases the danger of snow blind less, sunburn and long - term skin cancer. UV lights also reflected snow and ice, which can produce temperature of 40 to 42 degrees centigrade in enclosed spaces. In tents heat exhaustion becomes a real danger. It also causes dehydration as result of hyperventilation and increased work.
AMS will be apparent within four to 36hrs of ascent to the altitude of 25,00 to 3,000m after ascent. The rate at which different individuals acclimatize is unaware and continues the ascent, it may lead to HACE.
Myalgia, high fever or diarrhea is not a part of AMS; Physical examination is equally nonspecific and usually normal. ACCORDING TO THE ACUTE Mountain Sickness (AMS) self-assessment (The Lake Louise Consensus Scoring of AMS-Canada), individual will suffer headache with at least a few hours stay at the new altitude with gain in altitude:
HACE:
Requires one to three day to develop. Sometimes progression to HACE from mild AMS occurs in 12 hours also. It is an end stage of severe AMS in the event of rapid rise in altitude, either with a presence of a change in mental status and or ataxia in a person with AMS. Tandem gait test is the best like catwalk. Symptoms of HACE are worst at night. Once coma develops, mortality is over 60 percent. HACE is characterized by Ataxia, extreme lassitude and altered level of consciousness in the from of confusion, impaired thinking, drowsiness and coma.
HAPE:
It usually occurs within two for days of ascent to an altitude of more then 2500m, most commonly on the second night, Younger persons i.e. less then 20 years of age are more susceptible.
Golden rules:
1. If an individual has development any sickness at an altitude, the symptoms are due to the altitude until proven otherwise.
2. If a person has developed any altitude symptoms, s/he should not go any higher.
3. If a person feels very ill or cannot walk heel to toe in a straight line, has short breaths at rest, descend immediately.
4. If a person has altitude illness, a responsible companion must always accompany him.
Recommendations: